Environmental Norms & Discharge Limits
Overview
The chemical industry is a major contributor to environmental pollution due to its diverse processes that generate significant emissions, effluents and hazardous waste. For Small and Medium Chemical Manufacturing Industries, compliance with environmental norms and discharge limits is critical to avoiding legal penalties, safeguarding public health and achieving sustainable growth. This section presents a comprehensive and highly informative analysis of environmental norms, discharge standards and best practices, focusing on wastewater, air emissions, hazardous waste management and soil and groundwater protection. It also includes a detailed discussion on compliance strategies, monitoring systems and potential penalties for violations.
🌊 Wastewater Discharge Limits:
Wastewater from chemical industries is characterized by high levels of organic and inorganic contaminants, heavy metals and toxic compounds. Compliance with discharge standards set by CPCB and SPCBs is mandatory.
A. Key Parameters and Discharge Limits:
| Parameter | Inland Surface Water | Public Sewers | Marine Coastal Areas |
|---|---|---|---|
| pH | 5.5–9.0 | 5.5–9.0 | 5.5–9.0 |
| Biochemical Oxygen Demand (BOD) | ≤ 30 mg/L | ≤ 350 mg/L | ≤ 100 mg/L |
| Chemical Oxygen Demand (COD) | ≤ 250 mg/L | - | ≤ 250 mg/L |
| Total Suspended Solids (TSS) | ≤ 100 mg/L | ≤ 600 mg/L | ≤ 200 mg/L |
| Oil and Grease | ≤ 10 mg/L | ≤ 20 mg/L | ≤ 20 mg/L |
| Heavy Metals (Pb, Cd, Hg, Cr) | As per CPCB norms | ||
B. Advanced Treatment Technologies:
Effluent Treatment Plants (ETPs):
- Primary Treatment:Sedimentation and filtration for suspended solids removal.
- Secondary Treatment:Biological processes like Activated Sludge Process (ASP).
- Tertiary Treatment:Membrane filtration, UV disinfection and RO.
Zero Liquid Discharge (ZLD):
- Involves Multi-Effect Evaporators (MEE) and Crystallizers.
Electrochemical Treatment:
- Effective for cyanide and phenol removal.
Advanced Oxidation Processes (AOPs):
- Ozone and Fenton's reagent for toxic organics.
🌬️ Air Emission Standards:
Air emissions include particulates, sulfur oxides (SOx), nitrogen oxides (NOx), VOCs and greenhouse gases. Stringent standards apply to stack emissions and ambient air quality.
A. Key Pollutants and Emission Limits:
| Pollutant | Emission Limit | Source |
|---|---|---|
| Particulate Matter (PM10, PM2.5) | ≤ 150 mg/Nm³ | Boilers, incinerators, material handling. |
| Sulfur Oxides (SOx) | ≤ 100 ppm | Combustion of sulfur-rich fuels. |
| Nitrogen Oxides (NOx) | ≤ 50 ppm | Combustion processes. |
| Volatile Organic Compounds (VOCs) | ≤ 20 mg/Nm³ | Solvent-based processes. |
B. Air Pollution Control Technologies:
- Bag Filters and ESPs:For particulate control.
- Wet Scrubbers:Effective for SOx and acidic gases.
- Thermal Oxidizers:For VOC destruction.
- Carbon Capture:CO₂ absorption and sequestration.
🗑️ Hazardous Waste Management:
Efficient management of hazardous waste is essential to prevent soil and groundwater contamination.
A. Key Requirements:
- Manifest System:Tracking hazardous waste movement.
- Safe Storage:Segregation and leak-proof containers.
- Incineration:High-temperature disposal.
- Plasma Arc:Conversion to inert slag.
🏞 Soil and Groundwater Protection Norms:
Contamination control through:
- Leachate Management:Impermeable liners in landfills.
- Bioremediation:Microbial degradation of hydrocarbons.
- In-situ Chemical Oxidation (ISCO):Oxidants for contaminant breakdown.
- Regular Monitoring:Installation of piezometers for groundwater testing.
📈 Compliance Best Practices:
- Environmental Management Systems (EMS):ISO 14001 certification.
- Continuous Monitoring:CEMS for real-time data.
- Waste Minimization:Resource recovery and recycling.
⚠️ Penalties for Non-Compliance:
- Fines:Up to ₹1 lakh per day of violation.
- Closure Orders:Issued by CPCB/SPCB.
- Criminal Prosecution:Under Environment Protection Act.
🏞 Benefits of Compliance:
- Operational Efficiency:Reduced waste management costs.
- Market Access:Eligibility for exports.
- Risk Mitigation:Lower environmental and legal risks.
Complying with environmental norms ensures not only regulatory safety but also builds a sustainable business model for Small and Medium Chemical Manufacturing Industries.